Health data sharing between Health Information Systems (HIS) is a challenge for the coordination of care and biomedical research. Semantic interoperability enables the sharing of the meaning of health data when the exchange is based on computer interpretable representations. It relies on the development of reference systems - information models ("templates") and terminologies - allowing a formal representation of health data based on international standards. Operational emergence of semantic interoperability primarily depends on HIS’ ability to integrate these systems of reference and also the adoption by healthcare professionals, of solutions to capture clinical information based on adapted user interfaces. As such, the interface terminologies should be taken into account and also their formal representation using the reference terminologies. The objective of the Tersan project is the development of solutions for semantic annotation of clinical data structures (ordered or structured results documents for laboratory, pathology, radiology, etc.) according to systems of reference for semantic interoperability enabling their sharing and exploitation by HIS from distinct health facilities. For this, we need to develop a management platform for systems of reference, and implement tools and services that enable their integration within the HIS. The innovative characteristic of the project is to manage within this platform, in addition to health reference terminologies (such as ICD10/ICD11, ADICAP, LOINC, SNOMED 3.5 VF, CCAM, etc.), other types of semantic resources (models of data structures ("templates") and interface terminologies) which are essential to the emergence of an effective and large scale use of these reference terminologies. It is planned, in respect of governance of the ASIP Santé, to contribute to the implementation of a strategy for production, maintenance and sustainable distribution of national systems of reference for semantic interoperability. Operationally, the Tersan project will demonstrate, in the field of laboratory, pathology or radiology orders, that synchronization between HIS of systems of reference including interface terminologies, allows easy implementation of cross institutions processes (such as ordering an investigation in a health facility, making it in a second one, and integrating the results of this investigation in a third one). In addition, the project will demonstrate that health data entry in accordance with the systems of reference will allow, in every institution, standardized exploitation for personalized access to medical knowledge, clinical guidelines or ongoing clinical trials. The issues addressed in this project require research in the field of Information and Communication Technologies (ICT) (knowledge engineering, model-driven engineering, terminology and ontology engineering, information retrieval) to be conducted in a multidisciplinary context (health professionals, information science specialist, knowledge engineers, and terminologists).